The present invention relates generally to the capture and detection of aerosolized agents, such as, for example, chemical or biological biowarfare agents, and, more particularly to systems for and methods of continuous sampling and analysis of aerosol samples potentially containing such agents.
As the anthrax mailings of October of 2001 demonstrated, a number of vectors are available to the terrorist bent on social disruption. Biological warfare agents have long been a domestic terror concern and the use of the mails as a delivery method has many serious consequences. Not only are mail recipients at risk, but all those who handle or are in the vicinity of the mail piece during processing are at risk as well. In the extreme case, a few strategically posted items could bring a nation's postal administration, such as the United States Postal Service, to a complete halt. If mail delivery were to cease, even for a few days, the impact to trade, commerce, finance and general communication is incalculable.
Thus, it is desirable to capture and identify aerosolized particulate matter that may issue from sources requiring monitoring. Such sources could include mail pieces being sorted or otherwise processed, building ventilation systems, import and export cargo and military point detection systems.
Prior attempts to detect and identify pathogens in the mail use chemical or bio fluorescence methods. An example of a chemical method is Polymerase Chain Reaction (PCR). PCR is a DNA amplification technique that has been used successfully in laboratory environments in recent years. PCR is a powerful and useful technique but it does not generate results in real-time. The fastest PCR systems require a minimum of 30–60 minutes to process a sample and render a result. This time lag is problematic, as the mail piece containing the hazard will have traveled further down stream potentially affecting postal workers or postal customers. Other techniques using multi spectral ultra-violet (UV) fluorescence techniques may render a result quickly, but are prone to false alarms and are often non-specific relative to the threat. For example, non-threatening biological particulate in the right size range will typically cause a UV sensor system to indicate a false positive detection. Also, even if hazardous particles are correctly detected, UV based sensors will typically indicate the presence of the threat without specifically identifying the agent.